Hi,im travelling to china independently & have booked hotels myself. How do I get invitation letter?

Do you have a friend in China? If you have, you can ask your friend to issue you an invitation letter. If you do not have, you can try to find a tour agency in China to ask whether they can issue you an letter.

Personally speaking, if you can provide your hotel bookings and round trip tickets, you can apply a Tourist visa with these two documents and the invitation letter is not needed.